Plate heat exchanger



May 24, 1960 M. c. rHoMsoN 2,937,856

PLATE: HEAT EXCHANGER Filed Jan. 26, 1956 2 Sheets-Sheet 1 ler-2556 INVENTOR MEREmTH C. THOMSON,

May 24, 1960 M. c. THOMSON 2,937,856 PLATE HEAT EXCHANGER Filed Jan. 26, 1956 2 Sheets-Sheet 2 lNveNroR MEREDWH C. THOMSON 'WVM Y @gf/424W man United States Patent PLATE HEAT EXCHANGER Meredith C. Thomson, Oconomowoc, Wis., assignor to Kusel Dairy Equipment Co., Watertown, Wis., a corporation of Wisconsin Filed Jan. 26, 1956, Ser. No. 561,517 4 Claims. (Cl. 257-245) This invention relates to plate type heat exchangers and particularly to a plate heat exchanger incorporating a novel six-port plate which permits considerable economy in design and manufacture of such heat exchangers.

The principal object of this invention is to provide a plate for use in plate heat exchangers which will permit extreme latitude in use and will enable elimination or reduction of the number of terminal headers in the heat exchanger.

Another object of this invention is to reduce the cost of plate type heat exchangers.

Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modications of the single embodiment shown in the drawings in which:

Fig. 1 is a plan View of one forrn of a six-port plate designed according to this invention;

Fig. 2 is a section taken as indicated by line 2-2 on Fig. 1;

Fig. 3 is a partly schematic exploded perspective view of a portion of a section of a plate heat exchanger. 'Ihe left-hand part of Fig. 3 connects with the right-hand part of Fig. 4;

Fig. 4 is a continuation of the view shown in Fig. 3 and the left-hand part of Fig. 4 is adapted to connect to the right-hand part of Fig. 5;

Fig. 5 shows the remainder of the apparatus described with respect to Figs. 3 and 4; and

Fig. 6 is a chart showing the code used in showing the flow paths through the heat exchanger shown in Figs. 3, 4 and 5. K

Fig. 1 illustrates a sample plate used in a plate type heat exchanger. This plate 30 is provided with a central corrugated portion 32' which has a generally herringbone pattern and is surrounded by a gasket 34 which includes port 1 in the upper left corner of the plate and a blank space or port area at the lower right corner which could be punched out as shown in dotted lines to provide port 6. Ports 2, 3 and 4 are punched out and are surrounded by annular gaskets 36. Port 5 is shownin` dotted lines to indicate that it also could be punched out if desired. Thus, there are six possible port locations on the illustrated plate.

As is well known in the art, these plates are generally employed in heat exchangers where the plates are compressed one against the other and against the front head 38 until a sealed relationship is obtained between all plates. At this time the spacing between adjacent plates is the compressed height of the gasket material. These gaskets are located on one face of each plate or could, if desired, be located on both sides of alternate plates. For purposes of illustration of the sample system shown 'in Figs. 3, 4 and 5, the gaskets are shown as being on one faceV only. The illustrated plates are incomplete in so far as they are not provided with top hangers or lower guides which generally comprise part of the plate but form no part of the present invention and hence are not shown. Similarly, the usual vframes, etc. are not shown.

Plate heat exchangers are designed so that Huid llows in ,the space between the plates rin a thin iilm commonly referred to as a pass The placement of the gasket surrounding the pass will determine which one of the upper three port areas will be connected with one of the lower threerport areas. It is to be noted that reference is made to port areas and not to ports since a port area may or may not be punched out. Referring back to lFig. 1, the coding of the illustrated plate is set out adjacent the figure. The code in this case is 16-1234. This means that the flow is between port area 1 and port area 6 and thus the gasket is arranged as shown in Fig. 1.

The numbers appearing after the dash indicate which Y The illustrated system shows a pasteurizing system l made up of three sections; cooling, regeneration and heating. In the cooling section the pasteurized milk is cooled by well water while raw milk is passedvdirectly throughV the cooling section to the regeneration section. In the regeneration section the pasteurized milk gives up heat toV the incoming raw milk to preheat the raw milk for the heat section while cooling the pasteurized milk. In theV heat section raw milk is heated further by hot wateruntil at the end of the heat section it has reached the pasteurizing temperature. It then leaves plate 1 and passes through the divider plate 40 into the front head 38 which, in this case, is provided with an internal serpentine holding coil which may be of the `design shown in co-pending application Serial No. 534,782, now Patent 2,838,288y granted June l0, 1958.

the regeneration section by passing directly throughlhe plates in the heat section without making any passes. Now turning to the system in detail and starting at the -front head, it will be noted that the pasteurized milkY noted by the dashed line enters at port 2 on the front.

head and goes through port 2 on the divider plate and then goes through port 2 on each of plates 1, 2, 3,v 4, 5,'

6, 7, S and 9 which, in other Words, conveys the,V pasteurized milk directly through the heat section tolthe regeneration section just as if it were flowing through a pipe. In the regeneration section at plate `teurized milk comingthrough port 2 is split into two parallel passes. on plate 10 from port 2 to port area 4 while pasteurized .milk also goes directly through port 2 in plate 11 to port y2 in plate 12 where a pass is then made across plate 12 to port 4. Thus, the ow here is in parallel across plates 10 and 12. This is known as a group of two passes.

The ow from plate 10 joins the ilow at plate 12 by passing through port 4 in platesll and 12. The recombined iiow then passes through port 4 in plate 13 to port A4 in plate 14 where the :dow is again split for another group of two passes across plates 14 and 16. At plate 16 the, flow from the two passes is recombined and it all passes through port 3 in' plate 17 to port 3 in plate18 for a'Y This is `known as a group of onev pass. Next is a group of one pass at plate 20 and againV at plate 22 with the now. cooled pasterized milk leavingV through port 3 in plate 17 to port 3 in plate 18 for a pass from 3 to 4.

section it will be noted that alternate passes constitute Onleaving the front head and holding coil, the milk is pasteurized and is returned to` 10 the pas# Thus, a pass of pasteurized milk is made,

flow of raw milk between the plates (the raw milk being shown by the dot-dash line) and thus the raw milk is heated by the hot pasteurized milk as the raw milk progresses towards the right. The pasteurized milk is being cooled as it progresses towards the left inv all views. In the cooling section wherethe pasteurized milk passes between alternate plates, the other alternate passes are well water which is used for cooling purposes. The Well water is denoted by the short dash lines.

Thus, in the cooling stage the well water entersV at port 1 on gasket plate 42 and goes through port 1 on plates 22, 21. At plate 21 the flow of well water is split for a pass rfrom 1 to 5 while the remainder goes on through plate 20 `to plate 19 for a pass from 1 to 5. Thus, here the well water makes one group of two passes. The split tlow is recombined and then goes to port area on plate 17 where it makes a pass 5 to 2 and then is directed out of the cooling section by passing through aligned ports 2 in plates'18, 19, 20, 21, 22 and 42.

The raw milk enters gasket plate 42 and passes directly through the cooling section by passing. through port 6 in plates `22, 21, 20, 19, 18, 17, 16 to plate 15 where it splits to make a group of two passes with one pass being 6 to 1 across plate 1S and the other pass being 6 to 1 across plate 13. The flow is recombined through ports 1 in plates 15, 14 and 13 and then passes through port 1 in plate 12 to plate 11 where it splits again for one group of two passes. One of these passes is 1 to 6 on plate 11 and the other is 1 to 6 on plate 9. After plate 9, the raw milk is recombined and enters the heat section through port 6 in plate 8. At plate 7 a group of a single pass is made 1 to 6 and then passes through port 1 on plate 6 to port area 1 on plate 5 where another group of a single pass is made and the raw milk then flows through port 6 on plate 4 for a single pass on plate 3 and then goes to plate 1 for. another group of a single pass.

The hot water comes in the front head through port 3, goes through the corresponding port on the divider plate 40 and continues down to plate 2 for a pass 3 to 4 and then continues to plate 4 for another group of a single pass 3 to 4 and then to plate 6 where it is split for a group of two passes 3 to 5 over plate 6 and plate 8. The ow from plate 6 and from plate 8 recombines and is directed back out of the heat section towards the right by passing through port 5 in plates 8, 7, 6, 5, 4, 3, 2, 1, 40 and the front head.

Thus, it will be seen that by employing a six-port plate such versatility in design has been achieved that three sections of a plate heat exchanger can be made to operate without use of any intermediate terminals. It is well known in this art that when a four-port plate is used, as has been customary up to this time, it is necessary to employ terminals between each section since the use of two processing fluids in one section required full use of both the top and bottom ports on a four-port plate. Therefore, to enter or exit any uid between sections it was necessary to employ a costly terminal. When a sixport plate is used in a two section heat exchanger considerable advantage is still realized. It is possible with the six-port plate to provide a simplied piping arrangement where desired since it is possible to enter and exit a fluid on the same end of the heat exchanger. If this were to be done with a four-port plate, only one group of passes could be used which would necessitate a parallel flow arrangement which puts a limit on capacity due to a drop otf in etliciency as the capacity of the unit increases.

The extreme latitude of design afforded by the six-port plate results in elimination of terminals and design for entry and exit of any uids at the same end without loss of eficiency and additionally permits all piping connections to be made either at the front head or at the follower. This is true in two and three-section plate type heat exchangers which covers most applications. If a foursection unit is desired, then it would be necessary to employ one terminal as opposed to the three terminals which would be required with a four-port plate.

Throughout the above description reference has been made to the four-port plate which is in common use in this industry today. There are eight-port plates made but these eight-port plates are so designed that they are actually the equivalent of four-port plates in that ports on the eight-port plate work in pairs. Each pair performs he functions normally performed by one port in the fourport plate. Therefore, the above remarks with respect to four-port plates are fully applicable to the eight-port plate of the prior art.

Since so many ow arrangements are possible with the six-port plate and since not all six ports are employed at any one time and, in fact, the number of port areas used will generally be four or five, it is ratherdilcult to delineate a single distinguishing feature which is fully applicable to all the various ow arrangements possible with the six-port plate and which still distinguishes over the prior art. However, it can be said that in all such arrangements of the six-port plate, there are at least two adjacent plates which are characterized by the fact that two (or more) ports are opened outside the pass area and the fluid owing through these two ports differs either in kind, state or direction of tow4 through the plates. A difference in state is here defined to include such examples as hot or cold water and raw or pasteurized milk. There is no way of hooking up the conventional fourport plate to satisfy these requirements. With respect to a three-section exchanger, an easily distinguishing feature is that there are no terminals employed between the sections. With respect to a two-section heat exchanger, if the processing tuids enter and leave the exchanger at the same end of the exchanger then a distinguishing feature would be that there may be more than one group of passes of a given tluid. If the tlow does not leave the exchanger at the same end it enters, then the distinguishing feature would be the lack of a terminal between the sections.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spiritof the invention or from the scope of the appended claims.

I claim:

l. A plate type exchanger comprising cooling, heating and regenerator sections arranged in end to end relation with the regenerator section interposed between the cooling section and the heating section, each of said sections comprising a plurality of plates provided with ports, said plates being arranged in face to face spaced relation with certain of said ports in adjacent plates in the heater section being aligned and certain of said ports in adjacent plates in the cooling section being aligned, gasket means peripherally sealing adjacent plates, port gasket means sealing said aligned ports, said plates, ports, and the gaskets together defining three separate duid tlow passages through said heat exchanger, said tluid ow passages including a passage through the cooling section for a cooling fluid, a passage through the heating section for a heating tluid, and a passage `for tluid to be heated, said last-mentioned passage having an inlet port and an outlet port in the end plate of the cooling section remote from the regenerator section and leading from the inlet port serially through the cooling section, the regeneratorV section and the heater section, and then back through the heater section, the regenerator section and the cooling section to the outlet port, the first pass through the cooling section and the second pass through the heater section being direct passes through said aligned ports in the adjacent plates of said sections. e

t 5 Y 2. The plate type heat exchanger described in claim 1 wherein the first pass of the passage for the uid to be heated through vthe regenerator section includes transl be heated through the heatersection and the second pass of saidpassage throughthe cooling section include transverse passes across the faces of and between adjacent plates in said sections, the opposite faces of which plates define in part the uid ilow passages provided therein for the heating Aiiuid and Ifor the cooling Huid respectively.

3. The plate type heat exchanger described in claim 1 wherein the passage for the cooling uid terminates at opposite ends in an inlet port and an outlet port provided insaid end plate of the cooling sectionr'remote fromrv the regenerator section.

4. The plate type heat exchanger described in claim 1 vwherein the passage for the heating iluid terminates at opposite ends in an inlet port and an outlet port pro-y vided in said end plate of the heater section remote from the regenerator section.

References Cited in the le of this patent UNITED STATES PATENTS 2,248,933 Asile July 15, 1941 2,392,021 Wildermurh 1 Jan. 1,1946

FOREIGN PATENTS 73,221 Denmark oct. 1s, 1951 74,565 Denmark Aug. 18, 1952 660,469 Great Britain of 1951 

